PARENT SESSION
Monday, August 7, 8:00-11:30 am
COS 5 - Paleoecology
L-12, Lobby Level, Cook Convention Center
Presiders: W Gosling
Amazonia: a legacy of disturbance?
Bush, Mark1, Silman, Miles2, 1 Florida Institute of Technology, Melbourne, Florida2 Wake Forest University, Winston Salem, North Carolina
ABSTRACT- The indigenous human population of Amazonia at the time of European Conquest was probably between 1 and 5 million. Recently it has been suggested that the influence of those peoples was so profound that pre-Columbian Amazonia has been likened to a Parkland. Several well-documented archaeological sites along the main Amazon channel and its tributaries demonstrate long-term occupation, substantial populations, and the ability to transform landscapes using fire and agriculture. What is not known is whether the ecological disturbance evident at these sites can be extrapolated basin-wide. The extent to which Amazonia is effectively a regrowth forest within one or two tree generations of profound and widespread disturbance could have a significant impact on the formulation of conservation policy and practice. The Parkland concept needs to be tested empirically. We present paleoecological reconstructions from three Amazonian lake districts in southern Peru (5 lakes), Ecuador (3 lakes), and Brazil (3 lakes). Each of these lake districts lies at least 15 km from a major river and comprises a group of closed basin (or nearly so) lakes. Sediment cores were raised from all lakes, radiocarbon dated, and analyzed for their fossil pollen and charcoal content. In each district at least two of the lakes had formed by 7800 cal. yr BP and at least one of the lakes showed a long (>7000 year) history of occupation. Human presence and landuse was inferred from the presence of elevated amounts of charcoal, and the pollen of weedy species and crops. The influence of human activity was uneven but declined with distance from the inferred center of occupation. We suggest that assertions of landuse based on known high-density occupation sites are unwise and potentially misleading, especially for interfluvial habitats.
Key words: tropical forest, paleoecology, fossil pollen